php实现将任意进制数转换成10进制的方法

本文实例讲述了php实现将任意进制数转换成10进制的方法。分享给大家供大家参考。具体如

本文实例讲述了php实现将任意进制数转换成10进制的方法。分享给大家供大家参考。具体如下：

php将任意进制的数转换成10进制，例如8进制转换成10进制，16进制转换成10进制

<?php
# Show the steps involved in converting a number 
# from any base (like octal or hex) to base 10
# See below for examples, instructions and copyright
function show_convert_to_base_10 ($number, $base)
{
 // If the number contains a decimal component
 if (strstr ($number, '.'))
 {
 // Get the integer and decimal components
 list ($integer, $decimal) = explode ('.', $number);
 }
 else
 {
 // The number is an integer
 $integer = $number;
 }
 print "<b>Convert the base $base number $number to a
 base 10 number:</b><blockquote>";
 print "Convert the integer component ($integer) of the
 number:<blockquote>";
 // Compute the value of the integer component
 // Loop through the integer digit by digit
 // Reverse the number for easier handling
 $integer = strrev ($integer);
 $length = strlen ($integer);
 for ($pos = 0; $pos < $length; ++$pos)
 {
 /*
 PHP lets you treat strings and numbers like arrays
 Specify an offset and get the character at that
 position
 */
 $digit = $integer[$pos];
 // Handle character values for digits
 // (for bases greater than 10)
 if (eregi ('[a-z]', $digit))
 {
 $digit_value =
 (ord (strtolower ($digit))
 - ord ('a')) + 10;
 $digit = "$digit ($digit_value)";
 }
 else
 {
 $digit_value = $digit;
 }
 // Multiply the current digit by the radix
 // raised to the power of the current position
 $result = $digit_value * pow ($base, $pos);
 print "Multiply the value of the digit at position
 $pos by the value of the radix ($base) raised
 to the power of the position ($pos):<br/>";
 print "$digit * $base<sup>$pos</sup> = $result
 <br/><br/>";
 $sums[] = $result;
 }
 print '</blockquote>';
 if (isset ($decimal))
 {
 print "Convert the decimal component (0.$decimal)
 of the number:<blockquote>";
 // Pad the number with a leading 0 so that we can
 // start at position 1
 $decimal = '0'.$decimal;
 $length = strlen ($decimal);
 for ($pos = 1; $pos < $length; ++$pos) {
 $digit = $decimal[$pos];
 // Handle character values for digits
 // (for bases greater than 10)
 if (eregi ('[a-z]', $digit))
 {
 $digit_value =
 (ord (strtolower ($digit))
 - ord ('a')) + 10;
 $digit = "$digit ($digit_value)";
 }
 else
 {
 $digit_value = $digit;
 }
 // Multiply the current digit by the radix
 // raised to the power of the current position
 $result = $digit_value * pow (1/$base, $pos);
 print "Multiply the value of the digit at
 position $pos by the value of the 1/radix
 ($base) raised to the power of the position
 ($pos):<br/>";
 print "$digit * 1/$base<sup>$pos</sup> =
 $result<br/><br/>";
 $sums[] = $result;
 }
 print '</blockquote>';
 }
 $sums = implode (' + ', $sums);
 eval ("\$base_10_value = $sums;");
 print "</blockquote>The value of the base $base number
 $number in base 10 is $base_10_value. <br/>";
 print "This number is derived from the sum of the values
 of the previous operations ($sums). <br/> <br/>";
}

希望本文所述对大家的php程序设计有所帮助。